# Yahoo! UI Library

### TreeView Widget 2.2.2

Yahoo! UI Library > treeview > YAHOO.widget.Node

## Class YAHOO.widget.Node - uses YAHOO.util.EventProvider

Known Subclasses:
  YAHOO.widget.HTMLNode YAHOO.widget.RootNode YAHOO.widget.TextNode

The base class for all tree nodes. The node's presentation and behavior in response to mouse events is handled in Node subclasses.

### Constructor

YAHOO.widget.Node `( oData , oParent , expanded )`

Parameters:
  `oData <object>` a string or object containing the data that will be used to render this node
  `oParent <Node>` this node's parent node
  `expanded <boolean>` the initial expanded/collapsed state

### Properties

#### _dynLoad `- private boolean`

We can set the node up to call an external method to get the child data dynamically.

#### _type `- private object`

The node type

#### children `- Node[]`

This node's child node collection.

#### childrenRendered `- boolean`

This flag is set to true when the html is generated for this node's children, and set to false when new children are added.

#### data `- object`

The data linked to this node. This can be any object or primitive value, and the data can be used in getNodeHtml().

#### dataLoader `- function`

Function to execute when we need to get this node's child data.

#### depth `- int`

The depth of this node. We start at -1 for the root node.

#### dynamicLoadComplete `- boolean`

Dynamically loaded nodes only fetch the data the first time they are expanded. This flag is set to true once the data has been fetched.

#### expanded `- boolean`

The node's expanded/collapsed state

#### hasIcon `- boolean`

The toggle/branch icon will not show if this is set to false. This could be useful if the implementer wants to have the child contain extra info about the parent, rather than an actual node.

#### href `- string`

The href for the node's label. If one is not specified, the href will be set so that it toggles the node.

#### iconMode `- int`

Used to configure what happens when a dynamic load node is expanded and we discover that it does not have children. By default, it is treated as if it still could have children (plus/minus icon). Set iconMode to have it display like a leaf node instead.

#### index `- int`

The index for this instance obtained from global counter in YAHOO.widget.TreeView.

#### isLoading `- boolean`

This is true for dynamically loading nodes while waiting for the callback to return.

#### multiExpand `- boolean`

Can multiple children be expanded at once?

#### nextSibling `- Node`

This node's next sibling

#### nowrap `- boolean`

Specifies whether or not the content area of the node should be allowed to wrap.
Default Value: false

#### parent `- Node`

Parent node

#### previousSibling `- Node`

This node's previous sibling

#### renderHidden `- boolean`

Should we render children for a collapsed node? It is possible that the implementer will want to render the hidden data... @todo verify that we need this, and implement it if we do.

#### target `- string`

The label href target, defaults to current window

#### tree `- TreeView`

Tree instance this node is part of

#### Properties inherited from YAHOO.util.EventProvider:

`__yui_events, __yui_subscribers`

### Methods

#### appendChild

`private Node appendChild ( childNode )`
Appends a node to the child collection.

Parameters:
  `childNode <Node>` the new node

Returns: `Node`
  the child node

#### appendTo

`Node appendTo ( parentNode )`
Appends this node to the supplied node's child collection

Parameters:
  `parentNode <Node>` the node to append to.

Returns: `Node`
  The appended node

#### applyParent

`boolean applyParent ( parentNode )`
Certain properties for the node cannot be set until the parent is known. This is called after the node is inserted into a tree. the parent is also applied to this node's children in order to make it possible to move a branch from one tree to another.

Parameters:
  `parentNode <Node>` this node's parent node

Returns: `boolean`
  true if the application was successful

#### collapse toggle style.

`void collapse toggle style. ( )`
Hides this nodes children (creating them if necessary), changes the

Returns: `void`

#### collapseAll

`void collapseAll ( )`
Recursively collapses all of this node's children.

Returns: `void`

#### completeRender

`string completeRender ( )`
Called when we know we have all the child data.

Returns: `string`
  children html

#### expand

`void expand ( )`
Shows this nodes children (creating them if necessary), changes the toggle style, and collapses its siblings if multiExpand is not set.

Returns: `void`

#### expandAll

`void expandAll ( )`
Recursively expands all of this node's children.

Returns: `void`

#### getAncestor

`Node getAncestor ( depth )`
Returns this node's ancestor at the specified depth.

Parameters:
  `depth <int>` the depth of the ancestor.

Returns: `Node`
  the ancestor

#### getChildrenEl

`HTMLElement getChildrenEl ( )`
Returns the div that was generated for this node's children

Returns: `HTMLElement`
  this node's children div

#### getChildrenElId

`string getChildrenElId ( )`
Returns the id for this node's children div

Returns: `string`
  the element id for this node's children div

#### getChildrenHtml

`private string getChildrenHtml ( )`
Called when first rendering the tree. We always build the div that will contain this nodes children, but we don't render the children themselves unless this node is expanded.

Returns: `string`
  the children container div html and any expanded children

#### getDepthStyle

`string getDepthStyle ( depth )`
Returns the css class for the spacer at the specified depth for this node. If this node's ancestor at the specified depth has a next sibling the presentation is different than if it does not have a next sibling

Parameters:
  `depth <int>` the depth of the ancestor.

Returns: `string`
  the css class for the spacer

#### getEl

`HTMLElement getEl ( )`
Returns this node's container html element

Returns: `HTMLElement`
  the container html element

#### getElId

`string getElId ( )`
Returns the id for this node's container div

Returns: `string`
  the element id

#### getHoverStyle

`string getHoverStyle ( )`
Returns the hover style for the icon

Returns: `string`
  the css class hover state

#### getHtml

`string getHtml ( )`
Returns the markup for this node and its children.

Returns: `string`
  the markup for this node and its expanded children.

#### getIconMode

`int getIconMode ( )`
Returns the current icon mode. This refers to the way childless dynamic load nodes appear.

Returns: `int`
  0 for collapse style, 1 for leaf node style

#### getNodeHtml

`string getNodeHtml ( )`
Get the markup for the node. This is designed to be overrided so that we can support different types of nodes.

Returns: `string`
  The HTML that will render this node.

#### getSiblings

`void getSiblings ( )`
Returns a node array of this node's siblings, null if none.

Returns: `void`
  Node[]

#### getStyle

`string getStyle ( )`
Returns the css style name for the toggle

Returns: `string`
  the css class for this node's toggle

#### getToggleEl

`HTMLElement getToggleEl ( )`
Returns the element that is being used for this node's toggle.

Returns: `HTMLElement`
  this node's toggle html element

#### getToggleElId

`string getToggleElId ( )`
Returns the id for this node's toggle element

Returns: `string`
  the toggel element id

#### getToggleLink

`string getToggleLink ( )`
Generates the link that will invoke this node's toggle method

Returns: `string`
  the javascript url for toggling this node

#### hasChildren

`boolean hasChildren ( checkForLazyLoad )`
Checks if this node has children. If this node is lazy-loading and the children have not been rendered, we do not know whether or not there are actual children. In most cases, we need to assume that there are children (for instance, the toggle needs to show the expandable presentation state). In other times we want to know if there are rendered children. For the latter, "checkForLazyLoad" should be false.

Parameters:
  `checkForLazyLoad <boolean>` should we check for unloaded children?

Returns: `boolean`
  true if this has children or if it might and we are checking for this condition.

#### hideChildren

`void hideChildren ( )`
Hides this node's children

Returns: `void`

#### init

`void init ( oData , oParent , expanded )`
Initializes this node, gets some of the properties from the parent

Parameters:
  `oData <object>` a string or object containing the data that will be used to render this node
  `oParent <Node>` this node's parent node
  `expanded <boolean>` the initial expanded/collapsed state

Returns: `void`

#### insertAfter

`Node insertAfter ( node )`
Inserts this node after the supplied node

Parameters:
  `node <Node>` the node to insert after

Returns: `Node`
  the inserted node

#### insertBefore

`Node insertBefore ( node )`
Inserts this node before this supplied node

Parameters:
  `node <Node>` the node to insert this node before

Returns: `Node`
  the inserted node

#### isChildOf

`private boolean isChildOf ( parentNode )`
Returns true if the Node is a child of supplied Node

Parameters:
  `parentNode <Node>` the Node to check

Returns: `boolean`
  The node index if this Node is a child of supplied Node, else -1.

#### isDynamic

`boolean isDynamic ( )`
Evaluates if this node's children should be loaded dynamically. Looks for the property both in this instance and the root node. If the tree is defined to load all children dynamically, the data callback function is defined in the root node

Returns: `boolean`
  true if this node's children are to be loaded dynamically

#### isRoot

`boolean isRoot ( )`
Evaluates if this node is the root node of the tree

Returns: `boolean`
  true if this is the root node

#### loadComplete

`void loadComplete ( )`
Load complete is the callback function we pass to the data provider in dynamic load situations.

Returns: `void`

#### refresh

`void refresh ( )`
Regenerates the html for this node and its children. To be used when the node is expanded and new children have been added.

Returns: `void`

#### renderChildren

`private string renderChildren ( )`
Generates the markup for the child nodes. This is not done until the node is expanded.

Returns: `string`
  the html for this node's children

#### setDynamicLoad

`void setDynamicLoad ( fmDataLoader , iconMode )`
Configures this node for dynamically obtaining the child data when the node is first expanded. Calling it without the callback will turn off dynamic load for the node.

Parameters:
  `fmDataLoader <function>` the function that will be used to get the data.
  `iconMode <int>` configures the icon that is displayed when a dynamic load node is expanded the first time without children. By default, the "collapse" icon will be used. If set to 1, the leaf node icon will be displayed.

Returns: `void`

#### showChildren

`void showChildren ( )`
Shows this node's children

Returns: `void`

#### toggle

`void toggle ( )`
Expands if node is collapsed, collapses otherwise.

Returns: `void`

#### toString

`string toString ( )`
Node toString

Returns: `string`
  string representation of the node

#### Methods inherited from YAHOO.util.EventProvider:

`createEvent, fireEvent, hasEvent, subscribe, unsubscribe, unsubscribeAll`

### Events

#### parentChange

`parentChange ( )`
The parentChange event is fired when a parent element is applied to the node. This is useful if you need to apply tree-level properties to a tree that need to happen if a node is moved from one tree to another.

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